Modern mining vehicles and equipment are increasingly being made electrified. The benefits of battery-powered electric drive systems are magnified when underground. No local exhaust products are produced, thereby removing or reducing the need to ventilate exhaust products from mineshafts and reducing or eliminating detrimental health effects on miners.
However, battery electrification of mining vehicles is not yet practical or possible in many situations. Haul trucks, for instance, often must ascend rising mine tunnels or pathways, a task which results in rapid drain on a vehicle battery, more so if the haul truck is fully loaded. Conventional solutions include providing charging stations at a strategic point along the tunnel on each level. While this works, it lacks acceptable efficiency. It is not unusual for a haul truck arriving at the top of a ramp to require an immediate hours-long charging stop. This necessitates an increased number of electric haul trucks in order to achieve the same level of overall productivity provided by a fleet of diesel hall trucks, which increases cost and complexity to mining operations.
Another conventional solution is to increase the size of the battery. However, in addition to practical limits to battery size in mining vehicles, larger batteries tend to be more costly, tend to reduce efficiency due to the increased energy needed to move the battery itself, and require increased time to charge.
Another known solution is described in U.S. Pat. No. 9,545,854 to Daum et al. In this patent, an energy management system calculates estimated electric loads of powering motors over one or more segments of a trip according to designated operational settings of a trip plan. The energy management system communicates a demanded amount of electric energy to one or more of plural wayside stations disposed along the route so that the wayside stations have sufficient electric energy to charge an onboard energy storage device with the electric energy to meet the estimated electric loads. The energy management system can modify a trip plan based on load parameters and charging restrictions.